RS485 communication

[Neby2]

I am pretty new to this. I am trying to control a motor over a frequency inverter. For that I am using an RS485 (LabVIEW version 2018, 32 bits). Now when I try to communicate with the inverter, it gives me the error "Error -1073807194 occurred at Property Node (arg 😎 in VISA Configure Serial Port (Instr).vi->Simple Serial.vi". What am I doing wrong?

[GerdW]

Hi Neby,

What am I doing wrong?

I guess there is something wrong in your VI!

(You would get much better answers once you attach your VI with all the settings you are using when running it…)

Btw. did you read the error explanation?

[Bob_Schor]

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@Neby2 wrote:

What am I doing wrong?

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The answer to the above question is you are giving us the error message, but failed to attach the VI (the "code") that caused the error.  If I look up that error code, LabVIEW says it means "The connection for the given session has been lost."  Maybe you forgot to "wire" a VISA Session to the Configure VISA function.  Maybe you forgot to connect the (physical) wire from your inverter to your RS485 port (exactly where is this port?  Real serial ports disappeared from PCs more than a decade ago, didn't they?).

Please attach your LabVIEW 2018 code, and tell us more about the hardware you are using, especially how the serial data (which I assume comes in on a DB25 plug) gets into your PC.

Bob Schor

[Neby2]

That is what I thought first, that is why I used an example code from the library and I got the same error.

I am using an EX-1309-T converter from the RS485 to an USB 2.0( I already checked the physical wire and the connections work). The port is on an Toshiba Tosvert VF-S15 frequency inverter. With that I am trying to control a motor.

Thanks for the quick answers.

[GerdW]

Hi neby,

I don't see any RS485 port in your image...

[Neby2]

I marked the RS458 connector.

[GerdW]

Hi neby,

oh, I'm sorry. I just looked for the RS485 pins among all those other pins at the border of the inverter diagram…

When the error occurs right in ConfigureSerialPort then something must be wrong with your COM port hardware or it's drivers. Maybe it doesn't like one/some of those properties?

[Ben]

Not all RS-485 widgets are created equal.

It may be balking on the flow control setting.

Look inside the Serial config VI to see which settings are being touched and use explicit property nodes for each of those settings and get rid of the generic serial config VI.

There are other property nodes for rs-485 to configure 2 vs 4 wire etc.

Ben

[Ben]

Look at;

Help >>> Find Examples >>> Browse >>> Hardware Input and Output >>> Serial >>> RS-485 Transceiver Control.vi

To start out.

Ben

[Neby2]

Hi Ben

That did help. Now I am standing in front of another problem. In the manual it says that the MODBUS-RTU protocol of the inverter supports only part of the code, everything will be in binary. This means I do not have to use an Modbus in LabVIEW but I need to do a data conversion, right?

Thanks